Breast pump

ABSTRACT

A pump apparatus and method for extracting breast milk is disclosed. The pump includes a first interface component to stimulate a Milk Ejection Reflex (MER) and a second interface component to extract breast milk. Milk is extracted through an improved method that more closely replicates the suckling of an infant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/403,578, filed Jan. 11, 2017, which is hereby incorporated byreference in its entirety.

FIELD OF INVENTION

The present invention relates generally to milking and breast pumpdevices and, more particularly, to breast pumps for lactating femalesdesigned to mimic the natural suckling action of an infant duringbreast-feeding.

BACKGROUND OF THE INVENTION

Newborns and infants experience immediate and long-term benefits frombreast milk feeding that are well documented. (See Cunningham A. S.,Jelliffe D. B., Jelliffe E. F., Breast feeding and health in the 1980s:a global epidemiological review. Journal of Pediatrics. 1991, 118:659-666). These benefits include providing protection against manyillnesses caused by allergies, bacteria and viruses, such as stomachviruses, respiratory illnesses, ear infections, meningitis and the like.(See Fallot M. E., Boyd J. L., Oski F. A., Breast-feeding reducesincidence of hospital admissions for infection in infants. Pediatrics.1980, 65:1121-1124). Breast milk feeding also may increase intelligenceand fight obesity.

Nursing mothers may desire to impart the above-noted benefits of breastmilk to their infant when the two are separated. Additionally,traditional nursing may not be possible or convenient at all times andlocations. Thus, to extract breast milk to later feed to the infant,nursing mothers can use a breast pump. The extracted breast-milk can befed to the infant using a bottle fitted with an artificial teat.

In order to remove milk, a milk ejection reflex (MER) must first occur.The mechanism to initiate an MER is not precisely understood, and is notalways readily reproduced with available commercial breast pumps.

Commercial breast pumps use vacuum (negative air pressure) applied tothe mother's breasts to extract milk. Such devices are typically large,loud and energy-inefficient, compromising discretion and portability.Moreover, vacuum to extract breast milk is completely different than thesuckling action of the infant; in which the infant's mouth is filledonly with liquid, no air. Worse still, breast pumps using only vacuumcan cause significant pain or even edema in nursing mothers.

Therefore, it is desirous to provide an improved approach to breastpumps that more closely mimics the natural suckling action of theinfant, is discrete in use and does not cause pain or edema.

SUMMARY OF THE INVENTION

The present invention provides a breast pump that more closely mirrorsthe natural suckling action of an infant, and as a result improves uponthe collection of breast-milk generally associated with breast pumps.

According to the present invention, a device for extracting breast-milkfrom a breast, includes a funnel-shaped portion configured to receiveand seal against the breast, a neck portion extending from thefunnel-shaped portion including a proximal end and a distal end adaptedto receive and position a nipple of the breast, a feed channel definedat the distal end of the interior of the neck portion, a one-way valvelocated between the feed channel and a collection container, wherein thecollection container is located downstream of the one-way valve, aunitary and hermetic expandable and contractible first interfacecomponent configured to initiate an MER disposed within the device, aunitary and hermetic expandable and contractible second interfacecomponent disposed at the bottom of the neck portion toward the distalend and configured to create suction and to compress the nipple againstan inner surface of the neck portion, a pump to actuate the interfacecomponents, and a valve switch to select which interface component is tobe activated.

According to the present invention, a hydraulic milking machine includesa funnel-shaped breast shield, a nipple tunnel portion extending fromthe funnel-shaped portion including a proximal end and adownward-curving distal end, a unitary and hermetic expandable andcontractible first bladder configured to initiate an MER disposed at thejunction of the funnel-shaped section and neck portion, a unitary andhermetic expandable and contractible second bladder configured tocompress the nipple against an upper inner surface of the neck portion,and a hydraulic pump operatively connected to the first or secondbladders through a valve switch that selects which bladder is to beactivated by the pump.

According to the present invention, a method of extracting milk includesproviding a pumping head with a unitary and hermetic expandable andcontractible first bladder and a unitary and hermetic expandable andcontractible second bladder disposed within the pumping head, whereinthe second bladder may contain two sections, with the first sectionbeing more resilient than the second section, providing a hydraulic pumpwith a valve switch, which connects the hydraulic pump to either thefirst bladder through the valve switch via a first tube or to the secondbladder through the valve switch via a second tube, inserting a breastinto the pumping head, turning the connected pumping head and hydraulicpump to an on position, initiating a stimulation phase by the hydraulicpump delivering fluid to the first bladder, expanding and contractingthe first bladder against and away from the breast, then, after apre-set period of time or sooner if the user desires, switching thevalve switch to deliver fluid to the second bladder, compressing anipple of the breast via the more resilient first section expanding andcontracting more rapidly than the less resilient second section, andcollecting milk excreted from the nipple via a feed channel and throughthe check valve.

These and other objects, features and advantages of the presentinvention will become apparent in light of the detailed description ofembodiments thereof, as illustrated in the accompanying drawings.

As described herein, the term “vacuum” is used to connote negative airpressure, i.e. air pressure below atmospheric, whereas “suction” is usedto connote negative pressure, i.e. pressure below atmospheric, inair-filled or liquid-filled systems. The term “positive pressure” isused to connote fluid pressure, air or liquid, above atmosphericpressure. “Expandable”, “inflate”, “inflated”, “inflating”, or similarterms, are used to connote an increase in size caused by applyingpositive fluid pressure to a bladder, i.e. pumping fluid into thebladder. “Contractible”, “deflate”, “deflated”, “deflating”, or similarterms, are used to connote a decrease in size caused by applyingnegative fluid pressure to a bladder, i.e. removing fluid from thebladder.

Additionally, “proximal” and “distal” are used in their medical senseand directionally with respect to the user. Thus, “distal” is farthestfrom the user, and the “distal portion” of the nipple is the portiondrawn deepest into the pump. “Bottom,” “lower” or “down” signify adirection toward the milk collection container. Conversely, “top,”“upper” or “up” refer to a direction away from the milk collectioncontainer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross section view of a breast pump head including afunnel-shaped breast shield section, a first interface component, areceiver section, a second interface component, and a milk collectioncontainer, in accordance with embodiments of the present invention.

FIG. 1B is a cross section view of a breast inserted within the breastpump head of FIG. 1A, in accordance with embodiments of the presentinvention.

FIG. 2A is a cross section view taken across line A-A of FIG. 1A showingthe receiver section and the first interface component of FIG. 1A whendeflated, in accordance with embodiments of the present invention.

FIG. 2B is a cross section view taken across line A-A of FIG. 1A showingthe receiver section and the first interface component of FIG. 1A wheninflated, in accordance with embodiments of the present invention.

FIG. 3 is a cross section view taken across line B-B of FIG. 1A showingthe receiver section and the deflated second interface component of FIG.1A, in accordance with embodiments of the present invention.

FIG. 4 is an enlarged view of the receiver section of FIG. 1A includinga second interface component in accordance with another embodiment ofthe present invention.

FIG. 5A is a cross section view of the second interface component ofFIG. 4 in a fully deflated initial position, in accordance withembodiments of the present invention.

FIG. 5B is a cross section view of the second interface component ofFIG. 4 at a slightly inflated configuration, in accordance withembodiments of the present invention.

FIG. 5C is a cross section view of the second interface component ofFIG. 4 in a fully inflated position, in accordance with embodiments ofthe present invention.

FIG. 6 is a schematic illustration of a pump including a motor, controlelectronics, various sensors, control elements and control panel, inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following descriptions of the figures will convey details ofconstruction and operation of a breast pump in accordance with thepresent invention.

Referring to FIGS. 1(A) and (B), an assembled pumping head 10 forextracting milk includes a funnel-shaped breast shield section 12sealably connecting a breast 14 to a collection container 16 through adistally curved and hollow receiver neck section 18. As illustrated, thefunnel-shaped breast shield section 12 narrows to the receiver necksection 18 through a transition section 20. The receiver neck section 18includes a proximal end located adjacent to the transition section 20and a distal end positioned away from the transition section 20 and thefunnel-shaped breast shield section 12. Preferably, the distal end ofthe receiver neck section 18 is closed off so that the channel formedwithin the pumping head 10 feeds to a feed channel 21. In operation,when a breast 14 is placed in the pumping head 10 to extract milk, themilk will feed through this feed channel 21 then though a check valve 22to be collected in the collection container 16.

The receiver neck section 18 includes a top surface 23 and a bottominterior surface 24 forming a hollow and nominally cylindrical areaadapted to receive a nipple 26 when the user's breast is inserted intothe pumping head 10. The receiver neck section 18 further includes adownward curving section 28 at its distal end. Specifically, thedownward curving section 28 curves at an angle of approximately ninetyto one hundred and forty degrees relative to a longitudinal axis 29 ofthe receiver neck section 18. The entire interior surface of thereceiver section 18, including the downward curving section 28, issmooth to prevent surface imperfections from irritating the nipple 26and shaped to not inhibit milk collection.

In embodiments of the present invention, an annular unitary and hermeticfirst interface component 30 configured to mechanically stimulate thebreast 14 is disposed within the assembled pumping head 10. Morespecifically, the first interface component 30 is disposed at thetransition section 20, where the breast shield section 12 meets thereceiver neck section 18 and extends around the entire innercircumference/perimeter as shown in FIGS. 2(A) and (B). Additionally,the first interface component 30 is an expandable bladder filled withair or liquid for providing pulsating compression to the breast 14. Inalternative embodiments, the first interface component 30 may onlypartially cover the circumference of the funnel-shaped breast shieldsection 12 and/or receiver neck section 18 forming a “C” or “U” shape.Thus, in operation, only bottom, top, side, or angled compression may beapplied to an areola region of the breast 14 by the first interfacecomponent 30.

To maintain position, prevent milk leakage, and facilitate cleaning, thefirst interface component 30 may be bonded over the entire surface ofthe transition section 20 where the first interface component 30 touchesthe funnel breast shield section 12/receiver neck section 18 surfaces.Extending outward from the first interface component 30 and externallyaway from the pumping head 10 is a first tube or nozzle 32 that, asillustrated in FIG. 1(A), passes through a lower interior surface 34 ofthe pumping head assembly 10 to a first pump tube 36 (shown in FIG. 6).In embodiments, a first leak-proof rapid disconnect 38 may be disposedbetween the first tube 32 and first pump tube 36.

Disposed along the bottom interior surface of the receiver neck section18 is a unitary and hermetic second interface component 40 configured toinflate and deflate, and thus expand and contract within the pumpinghead 10. In some embodiments, the second interface component 40 is anexpandable bladder filled with air or liquid and has a uniform topthickness. In other embodiments, such as shown in FIG. 4, a proximalsection 42 of the top surface of the second interface component 40 isthinner than a distal section 44 of the top surface.

Referring back to FIGS. 1(A) and (B), extending outward from the secondinterface component 40 and externally away from the pumping head 10 is asecond tube or nozzle 46 that, as illustrated, passes through the lowerinterior surface 34 of the pumping head assembly 10 to a second pumptube 48 (shown in FIG. 6). In embodiments, a second leak-proof rapiddisconnect 50 may be disposed between the second tube 46 and second pumptube 48. The two leak-proof rapid disconnects 38, 50 may be situatedanywhere along the tubes 32, 46 running from the pumping head 10.

The downward curving section 28 leads into feed channel 21, which leadsto check valve 22 and then into the collection container 16 which can bea bottle or bag for collecting extracted milk. Specifically, the feedchannel 21 is located above the check valve 22. The check valve 22 isnormally-closed, and configured to allow milk to enter the collectioncontainer 16 while preventing air from leaking into the feed channel 21which would compromise liquid fill in the pumping head 10. In someembodiments, the check valve 22 is a duck-billed valve, although othervalves are also contemplated.

The collection container 16 may contain external threads 56corresponding to a female threaded collar 58 of the pumping head 10 forremovably connecting the collection container 16. In some embodiments,the collection container contains female threads while the pumping headcollar has external threads. Other means for connecting the collectioncontainer 16 to the pumping head 10 are also contemplated, such assnapping the collection container 16 with a flexibly formed top 59 intoa recessed grove 60, as shown in FIG. 1(B).

Referring to FIGS. 2(A) and (B), a cross-section of the transitionsection 20 across line A-A in FIG. 1(A) is shown.

The overall cross-section of the transition section 20 is substantiallycircular as the funnel-shaped shield section 12 narrows to the hollowreceiver neck section 18. As discussed in connection with FIG. 1(A), theannular first interface component 30 extends completely or partiallyaround the inner circumference/perimeter of the funnel-shaped shieldsection 12, transition section 20 and/or receiver section 18. When thefirst interface component 30 is deflated, the aperture through thefunnel-shaped shield section 12, transition section 20 and/or receiversection 18 is larger than when the first interface component 30 isinflated.

Referring to FIG. 3, a cross-section of the receiver neck section 18across line B-B in FIG. 1(A) is shown with the second interfacecomponent substantially deflated.

The overall cross-section of the receiver neck section 18 issubstantially round such that the neck section 18 generally forms acylindrical tube, although it may have other shapes, for example oval.For positioning, to prevent milk leakage and to facilitate cleaning, thesecond interface component 40 may be bonded where it touches the lowerinterior surface 34 and generally extend along the bottom interiorsurface 24 of the tubular neck section 18. In embodiments, and aspictured in FIG. 3, a fully deflated second interface component 40maintains the substantially round internal cross-section of the receiverneck section 18. In alternative embodiments, when inflated the secondinterface component 40 may sufficiently occupy the interior distalportion of the receiver neck section 18 such that compression may beapplied to the nipple 26 by the second interface component 40 so thatthe nipple 26 is completely compressed against the top interior of theneck section 18. These inflations and deflations of the second interfacecomponent 40 are intended to mimic the natural suckling action of aninfant.

Referring to FIG. 4, an enlarged view of the receiver neck section 18 ofFIG. 1(A) including a second interface component 40 in accordance withan embodiment of the present invention is shown. The proximal section 42of the top surface of the second interface component 40 is thinner thanthe distal section 44 of the top surface. The thinner proximal section42 allows it to stretch more easily than the thicker distal section 44which is stiffer and so more difficult to stretch. Thus when the secondinterface component 40 is expanding, the proximal section 42 will risein advance of the distal section 44. When the second interface component40 is contracting, the proximal section 42 will remain in an elevatedposition longer relative to the distal section 44. This operation ispictured in FIGS. 5 (A-C).

Referring to FIG. 5(A), in an initial position, the second interfacecomponent 40 is fully deflated. Referring to FIG. 5(B), in a slightlyinflated configuration, the proximal section 42 of the second interfacecomponent 40 is expanded and moves up to asymmetrically compress thenipple 26. Referring to FIG. 5(C), in a fully inflated position, thedistal section 44 of the second interface component 40 is now fully up,uniformly compressing the nipple 26. When deflating from the fullyinflated position of FIG. 5(C), the second interface component 40contracts asymmetrically to the slightly inflated position shown in FIG.5(B).

Referring to FIG. 6, a pump 61 actuated by a control panel 62 through aseries of control electronics 64 is shown. The pump 61 includes a piston66 housed within a cylinder 68. A motor 70 drives the piston 66 by apropulsion mechanism 71. The propulsion mechanism 71 can be, forexample, lead screws, a rack and pinion system, a crank and axle systemor other type of mechanism capable of extending and retracting thepiston 66. In preferred embodiments of the present invention, the pump61 is a hydraulic pump. In alternative embodiments, the pump 61 can be apneumatic pump.

The pump 61 shown in FIG. 6 is a piston 66 in cylinder 68 although anypositive displacement pump will suffice e.g. a diaphragm pump,peristaltic pump etc.

The control panel 62 includes an on/off switch 72, an MER button 73, amaximum MER pressure selector 74 and a maximum pump suction selector 76.The on/off switch 72 is configured to initiate the pump 61 through aseries of control electronics 64 controlled by a control logic 83.

The pump 61 further includes an electrically actuated valve switch 84 todirect pump suction or pressure from the cylinder 68 to the firstinterface component 30 via the first pump tube 36 or to the secondinterface component 40 via the second pump tube 48. A reservoir 86provides make-up liquid or air to the cylinder 68 of the pump 61.Similar to hydraulic and automotive braking systems, the pump 61 mayfurther include an air bleed 88 to exhaust air in the case of aliquid-filled system. Alternating current (AC) or batteries 90 canprovide power to the pump 61.

Position sensors, stepper motors, and other suitable sensors andelectronics may be included for controlling suction levels, suctionrates, pumping frequency and the like, without departing from the scopeof the present invention.

In embodiments, the pump 61 also includes a pressure sensor 92 connectedto the cylinder 68 and adapted to report real-time system pressure tothe control electronics 64.

In operation, the breast 14 is inserted into the breast shield section12 and the nipple 26 extends into the receiver neck section 18. Thesecond interface component 40, which was fully deflated at the end ofthe last pumping session during the shutdown sequence, allows the nipple26 to enter the nipple tunnel/receiver neck section 18 unimpeded. Thelocation of the first interface component 30 and/or the funnel shape ofthe shield section 12 establish a seal around the breast 14.

Next, the pump 61 is switched on with the on/off switch 72 disposed onthe control panel 62. The control electronics 64 start an initiationsequence by switching the valve switch 84 to the second interfacecomponent 40.

The activated pump 61 begins to cycle, alternately inflating anddeflating the second interface component 40. With each deflation,suction in the receiver neck section 18 increases, pulling/elongatingthe nipple 26. With each inflation of the second interface component 40,air in the receiver neck section 18 is squeezed out through the checkvalve 22.

The initiation sequence continues until the nipple 26 contacts (i.e. isseated against) the downward curving section 28. After air has beenexhausted the feed channel 21 is completely filled with liquid. In thisregard, an important function of the one-way check valve 22 is tomaintain separation between the liquid-filled feed channel 21 and theair-filled collection container 16 and, thereby, to maintain liquid fillin the pumping head 10.

At this point, the pressure sensor 92 will detect a sharp increase insuction when the nipple 26 seats against the downward curving section 28because the volume created by the downward motion of the secondinterface component 40 will no longer be absorbed by the nipple 26pulling/elongating to fill that created volume. Upon detection, thepressure sensor 92 reports the abrupt suction increase to the controlelectronics 64 and control logic 83. The control logic 83 and controlelectronics 64 are pre-set to then switch the valve switch 84 to thefirst interface component 30 in response to this abrupt suction changereport.

Next, the pump 61 and first interface component 30 initiate astimulation phase by alternately expanding the first interface component30 against the areola section of the breast 14 to cause compression andmassage to that region. Such compression may be, for example, onehundred to one hundred forty compressions per minute, preferably onehundred twenty compressions per minute for approximately two minutes.

The first interface component 30 can be a bladder or other expandablemembrane capable of expanding and contracting. In embodiments, the firstinterface component 30 is positioned such that the areolar region iscontacted completely around its circumference by the first interfacecomponent 30. In some embodiments, only the top and bottom of theareolar region are contacted. In other embodiments, only the lowerregion of the areolar is contacted. Further, it is understood that thefirst interface component 30 can be disposed anywhere within the shield12 or receiver neck section 18, but preferably at transition region 20and be bonded to some or the entire inner surface of the pumping head10, provided the first interface component 30 or other bladdersubstantially performs the functions described herein.

The user may select the maximum MER pressure using knob 74 disposed onthe control panel 62. A pressure feed back signal from the pressuresensor 92 allows for further fine-tuning pressure by the user.Inflation/deflation profiles are pre-programmed.

The stimulation phase ends after expiration of a set time (e.g. twominutes) or by pressing the MER button 73. After the stimulation phase,an MER has likely been initiated.

The MER button 73 is a toggle, which may be selected any time during thepumping session causing a change from MER stimulation to milk extractionor vice versa.

This initiation sequence may alternatively be performed in reverse. Thatis, the first interface component 30 may operate first followed aftertwo minutes or sooner if selected by the user, by the second interfacecomponent.

Additionally, the first interface component 30 and/or the secondinterface component 40 can be run under hot water to heat the componentsand any fluid contained therein. The warmth can also facilitate an MER.

After the preset time period or by the user pressing the MER button 73,the control electronics 64 cause the first interface component 30 todeflate, then cause the valve switch 84 to change back to the secondinterface component 40. The control electronics 64 then cause the secondinterface component 40 to inflate and deflate.

When the second interface component 40 begins to deflate, it moves downmore creating volume around and in front of the nipple 26. The volumecreated by the deflation pulls the check valve 22 closed and createssuction, which extracts milk into the feed channel 21. Morespecifically, the extracted milk is drawn into the “suction chamber,” avolume bounded by the nipple 26, the downward curving section 28, thedistal end of the second interface component 40 and the check valve 22.This milk extraction process utilizing suction in a liquid-filled systemmimics the natural suckling action of an infant.

When the second interface component 40 inflates two events occur. First,the nipple is compressed against the top surface 23 and/or downwardcurving section 28 of the receiver neck section squeezing the nippletissues and thereby preventing edema, an accumulation of fluid in thetissues. Edema is a common cause of pain during breast pumping withconventional air-filled breast pumps. This prevention of edema bycompression is analogous to the use of compression socks to control footswelling. Second, as the second interface component 40 inflates, itmoves up causing a change from negative to positive pressure in thesuction chamber. This positive pressure pushes the extracted milkthrough the check valve 22 and into the collection container 16.

In some embodiments, the top surface of the second interface component40 has a uniform thickness as shown in FIGS. 1(A)-1(B). In this case itinflates uniformly.

In alternative embodiments, the proximal section 42 of the top surfaceof the second interface component 40 is thinner than the distal section44, as shown in FIG. 4. Accordingly, when inflated, the more resilientproximal section 42 will rise in advance of the distal section 44.Conversely, when deflating, the proximal section 42 will fall later thanthe distal section 44. Thus, the proximal section 42 would lead oninflation and lag on deflation relative to the distal section 44.

The pump 61 actuates the piston 66 creating a pumping cycle of betweenforty and eighty, preferably about sixty cycles per minute. Maximumsuction for the second interface component 40 can be controlled throughfeedback from the pressure sensor 92 and the separate maximum pumpsuction selector knob 76 disposed on the control panel 62. The suctionrate curve to reach maximum suction caused by deflation of the secondinterface component 40 is pre-programmed. Inflation/deflation frequencyof the second interface component 40 is also pre-programmed or may belinked so that, for example, changing suction by knob 76 changesfrequency in a pre-programmed fashion or frequency may be controlled bya separate knob 78 on the control panel 62.

When the pumping session is complete, the on/off switch 72 on controlpanel 62 is switched to the off position and a shutdown sequence isinitiated. The valve switch 84 remains switched to the second interfacecomponent 40 until the second interface component 40 is fully deflated.Then the valve switch 84 switches to the first interface component 30,and fully deflates it. Control electronics 64 then switch off the pump61 and the unit is fully off.

The user can insert a finger into the receiver neck section 18 and breakthe residual vacuum from the breast 14 and the shield section 12.

Milk collected in the collection container 16 can be fed to an infant orstored for future use.

The leak-proof rapid disconnects 38, 50 allow the pumping head 10 to beseparated from the tubes/nozzles coming from the pump 36, 48 withoutlosing liquid from either part. After the rapid disconnects 38, 50 areseparated; the pumping head 10 can be cleaned. Alternatively, there maybe no disconnects and the pumping head 10 can be cleaned while stillconnected to the pump.

Additionally, the check valve 22 can be removed to facilitate cleaningthe pumping head 10. Any residual milk can be removed from the interiorof the funnel 12 and the receiver neck section 18 via a brush with soap,detergent and warm water.

One advantage of the bonding of the first interface component 30 and/orsecond interface component 40 is that the bonding holds the bladder inposition, and creates a liquid-tight seal. Thus, the pumping head 10 ofthe present invention avoids breast milk leakage out of the receiversection and prevents extracted milk from collecting under the bladder.This feature also facilitates cleaning of the pumping head assembly 10.

One advantage of the resilient proximal section 42 and second interfacecomponent 40 is that the rise and fall motion is akin to a rollingaction, allowing the proximal section 42 to “pin” the nipple 26 inplace, restricting the nipple's elastic retraction away from thedownward curving section 28 of the receiver neck section 18, when thesecond interface component is inflated. Consequently, embodiments of thepresent invention may further limit ineffective nipple 26 motion thatwould dissipate suction.

One advantage of the second interface component 40 is to compress thenipple 26 against the top surface 23 and/or downward curving section 28with enough force to prevent the pooling of blood and other fluids inthe nipple 26 tissues. The compression helps prevent edema—a painfulcondition caused by other commercially available breast pumps.

In embodiments solely using liquid to expand and contract the firstinterface component 30 and second interface component 40, the pump 61may deliver quicker and more precise actions and possibly with strongerforce than can be achieved with air-filled systems.

Another advantage of the hydraulic embodiments is that the pump 61 maybe physically smaller and more discrete, as the hydraulic embodimentspump will pump less than five percent the volume per cycle when comparedto air-driven pumps. Further, a less “hard working” pump can be quieterand more energy efficient, improving battery life, a great aid tomobility and ease of use.

Another advantage of the pumping head 10 of the present invention isthat the second interface component upward motion reduces volume in thepumping cavity (i.e. receiver neck section 18) and forces extracted milkthrough the check valve 22 and into the collection container 16. Mostcommercial air-driven breast pumps can develop vacuum only with noability to create positive pressure, and so they depend only on weightof the extracted breast milk to push it through the check valve. Thismethod does not work reliably, and milk often backs up into the vacuumline, sometimes contaminating the pump, and creating a very unhygieniccondition.

In another embodiment the entire interior surface of pumping head 10 maybe coated with a highly elastic material to form an adherent membranewhich covers the inside of funnel shield section 12, neck section 18,feed channel 21 and both the first interface component 30 and secondinterface component 40. Such an elastic membrane allows full andunrestricted expansion and contraction functioning of both bladderswhile preventing milk collection in small spaces inside the pumpinghead. This configuration will ease cleaning,

Additionally, the features of the present invention may also be used formilking machines. Specifically, the above described method and pumpinghead 10 may be used for the milking of animals.

Although this invention has been shown and described with respect to thedetailed embodiments thereof, it will be understood by those skilled inthe art that various changes in form and detail thereof may be madewithout departing from the spirit and scope of the invention.

It is noted that the Figures are to be taken as an illustrative exampleonly, and are not to scale.

Additionally, it is also to be understood that the terminology used iffor the purpose of describing particular embodiments only, and is notintended to limit the scope of the claims of the present invention.

What is claimed is:
 1. A method of extracting milk, the methodcomprising: providing a pumping head with an expandable and contractiblefirst bladder and an expandable and contractible second bladder disposedwithin the pumping head; providing a hydraulic pump with a valve switch;connecting the hydraulic pump to the first bladder through the valveswitch via a first tube; connecting the hydraulic pump to the secondbladder through the valve switch via a second tube; inserting a nippleof a breast into the pumping head; turning the connected pumping headand hydraulic pump to an on position; initiating a stimulation phase bythe hydraulic pump delivering fluid to the first bladder through a valveswitch and a first tube; expanding and contracting the first bladder byan alternating action of positive and negative pressure respectively,causing the first bladder to flex against and away from the breast for apre-set period of time to initiate a milk ejection reflex; initiating amilk extraction phase by switching the valve switch and having thehydraulic pump deliver fluid to and withdraw fluid from the secondbladder through the valve switch and second tube in alternating fashionbetween positive pressure to expand the second bladder and causecompression of the nipple against a solid surface to control edema andnegative pressure to contract the second bladder creating suction toextract milk; and collecting milk excreted from the nipple.
 2. Themethod of claim 1, wherein the stimulation phase causes between onehundred and one hundred forty compressions per minute of the firstbladder for two minutes or less.
 3. The method of claim 1, wherein themilk extraction phase causes expansion/contraction of the second bladderof between forty and eighty cycles per minute.
 4. The method of claim 1,wherein the expandable and contractible second bladder contains at leasttwo sections, wherein the first section is more resilient than thesecond section, and wherein the first section and second sectionasymmetrically compresses the nipple of the breast via the moreresilient first section expanding more rapidly than the less resilientsecond section.
 5. The method of claim 1, wherein the first and secondtubes further include leak-proof disconnects.